Carriage release for lathes



May 8, 1951 J. B. RUATTI CARRIAGE RELEASE FOR LATHES Filed Aug. 19, 1948 INVENTOR,

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Patented May 8, 1951 UNITED STATES PATENT OFFICE 5 Claims. 1

This invention relates to a carriage release for machine lathes.

A primary object of the invention is to provide a device which is readily applicable to most conventional forms of lathe which will enable stops to be set at any desired positions along the length of the lathe bed and which when engaged will automatically effect a release of the driving connection between the carriage and the lead screw in either direction so that regardless of the direction in which the carriage may be propelled by the lead screw an automatic stopping of the carriage may be effected.

More specifically, an object of the invention is to provide a construction applicable to the carriage of a lathe consisting of a driven gear segment applicable to the lead screw release crank on the carriage, the gear segment being in mesh with a driving gear which is spring propelled. A novel and simple means is effective to temporarily lock the driving gear against rotation under the effect of the spring so that when the crank is swung into a position to effect an engagement with the lead screw, it will be effective- 1y locked in this position until such time as a stop may be engaged and then be forcibly rtated by the spring to lead screw releasing position.

With the foregoing and other objects in view, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a view in front elevation of a portion of a lathe illustrating the mechanism embodying the present invention as having been applied to its carriage;

Fig. 2 is a view in front elevation on an enlarged scale a portion of the device illustrated in Fig.1;

Fig. 3 is a sectional view taken substantially upon the line 33 upon Fig. 1 in the direction indicated;

Fig. 4 is a vertical section taken substantially upon the line L- i upon Fig. 3;

Fig. 5 is a sectional View taken substantially upon the line 55 upon Fig. 4; and

Fig. 6 is a sectional view taken substantially upon the line 6-5 upon Fig. 1.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, It! indicates generally a lathe bed having rails H over which a carriage I2 is movable. 13 indicates the lead screw of the lathe to which the carriage may be optionally connected so as to be propelled thereby along the length of the lathe bed. Various types of devices are utilized for effecting a connection or disconnection between the carriage and the lead screw but in the usual lathe whatever mechanism is employed it is controlled and operated by a crank I i rotatably disposed on the forward side of the carriage. In some constructions of lathes the crank l iswings downwardly through approximately a ninety degree are to elfect engagement between the carriage and the lead screw and on swinging the crank upwardly through the same are a release of the connection between the carriage and the lead screw is accomplished. In other forms of lathe the movement of the crank is reversed, namely, upward swinging movement of the crank effects a connection with the lead screw and downward swinging movement accomplishes the disconnection. The present invention is applicable to either lathe or to other types of machine tools where similar or analogous conditions exist.

The present invention comprises a gear segment l5 which has an arm l6 rigid therewith with forwardly extending lips I? integral therewith adapted to embrace the sides of the crank l4. In applying this segment to the carriage of the lathe it is merely necessary to remove the crank M from the rotary shaft [3 on which it is mounted, slip the gear segment on the rotary shaft and reapply the crank in such a position that it will fit between the lips IT. The gear segment 15 constitutes a driven gear segment and when driven it may swing the crank M from the full line position shown in Fig. 2 to the dotted line position shown therein.

A housing 18a is provided which is adapted to be secured to the carriage [2 such as by cap screws l9. In applying this housing to the carriage it usually is necessary to drill and tap two holes designed to receive the cap screws l9. Within the housing there is rotatably fitted a driving gear 2i] which meshes with the gear segment iii. The hub of this driving gear is cylindrically recessed to receive a generally cylindrical cam 2| having a stem 22 integral therewith. A closure 23 closes the outer end of the housing and is adjustably held in position with relation to the housing by means of a set screw 24. This closure provides an anchoring means for one end of a torsion spring 25, the other end of which is anchored in the driving gear 28. The closure may be rotatably adjusted with relation tothe housing by inserting a pin P in one of the rod 39 extends.

A cam follower 29 is slidable radially through the wall of the hub of the driving gear 23 and has a length substantially equal to the wall thickness of the hub of the driving gear as shown in Fig. 4. The radial aperture in which the cam follower is disposed is indicated at 3!! and. is adapted to move into or out of registration with an aperture 3| in the housing IS. The aperture 3| contains a locking pin 32 of such a size that it may enter the aperture 30 in the hub of the driving gear 28, as shown in Fig. 4, the locking pin is normally urged into this position by means of a leaf spring 33 secured to the side of the housing such as by a screw 34 but it may be held in a retracting position such as that indicated on dotted lines in Fig. 4 by screwing a thumb screw 35 therethrough against the side of the housing.

The arm 21 carries a roller 36 which is engageable with either of a plurality of stops indicated at 31 and 38 which are adjustable along the length of a rod 39 that is arranged parallel'to the lathe bed. These stops may be of any preferred construction but are illustrated as consisting merely of tubular members it through which They are held in any adjusted position along the length of the rod by tightening shoes 4| against the rod by means of screws 42. members are arranged in the path of the roller 36.

The rod 39 is supported on the lathe bed by any suitable type of rod support such as two opposed plates 43 and 44. The plate 43 is adapted to be positioned against the forward side of the forward rail H and carries a pair of horizontally aligned studs 45. The plate M carries a similar stud 4B engageable with the rear side of the rail II and a bolt 41 tightens the two plates into clamping engagement with the rail. A vertical slot 59 in the plate 4 5 permits of vertical adjustment of the plate M with relation to the plate 43 and in relation to the rail and the carriage l2. The plate M carries a pair of forwardly extending studs 53 and 5| through which the rod 39 slidably extends. It is held in any adjusted position by means of screws 52.

The operation of the above described construction is substantially as follows. Assuming the lathe to have a crank M which swings downwardly to effect an engagement with the lead screw l3 downward swinging movement of the crank l4 causes the driven gear segment l5 to rotate therewith. This gear segment in turn rotates the driving gear 2!] winding up the torsion spring 25. At the time that the crank it is in its lowermost position apertures 36 and 3| come into alignment with each other and relief spring 33 is effective to press the locking pin 32 inwardly to enter aperture which is the inner end of the cam follower 29 to enter the notch in the cam 2|. The entry of the locking pin 32 in the aperture 39 in the hub of the driving gear 20 temporarily locks the driving gear against rotation by the wound up torsion spring 25. Con- The forward ends of these tubular sequently, the crank M will remain in its lowermost position wherein the lead screw I3 is engaged and the carriage |2 will be effectively driven or propelled along the lathe bed by the lead screw until such time as the stop 37 or the stop 38 is engaged. If one of these stops is engaged by the roller 36 on the arm 21 the cap 25 and the stem 22 will be turned thereby. The turning of the stem 22 efiects a rotation of the cam 2| forcing the cam follower 29 outwardly in the aperture 30. The cam follower in turn forces the locking pin 32 out of the aperture 3|] thus freeing or releasing the driving gear 20 so that it may be rotated by the wound torsion spring 25. Rotation of the driving gear 20 causes the driven gear segment I 5 to be rotated thereby thus swinging the release crank Hi from its lowermost position to its uppermost position and effecting a release of the carriage |2 from the lead screw l3. Thus, when either stop 31 or 33 is engaged by the roller 33 the carriage will be immediately and automatically disconnected from the lead screw and allowed to stop with relation to the lathe bed.

If the construction of the lathe is such that the release crank i l swings downwardly to release the carriage from the lead screw instead of upwardly as previously described the construction employed is the same with the exception that a reversely wound torsion spring 25 may have to be substituted for the torsion spring shown to urge the driving gear 29 in the opposite direction and consequently accomplish a swinging of the crank M in the opposite direction.

If, at any time, it is desired to render the construction nonoperable this is accomplished by merely screwing the thumb screw 35 through the leaf spring and against the housing i8 causing the leaf spring to shift to the dotted line position shown in Fig. 4 and holding the locking pin 32 in retracted position against entry in the aperture 38. Under these conditions, swinging of the crank M will drive the gear segment l5 and the gear 2'8 but as the locking pin 32 is held out of aperture 39 the driving gear is at all desired length.

From the above described construction it will be appreciated that a highly simple and advantageous carriage release for lathes has been provided which will automatically effect a stopping of the carriage at either end of a selected length of travel. The construction is applicable to any type of conventional lathe without requiring any serious modification of the lathe. The housing l8 and its associated structure can be applied to the carriage by merely drilling and tapping two holes in the carriage to receive the fastening screws l9. t is obvious that if the arm 21 with its roller 33 will effect a release when shifted in either direction that it is desired to stop the carriage at any intermediate position between the stops 3'! and 38 that this can be instantly accomplished by manually swinging the arm 21 in either direction.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A device of the class described comprising a driven gear segment applicable to the lead screw release crank of a lathe carriage, a driving segment arranged to mesh therewith, a cam rotatable in the driving segment, a cam follower slidable in the driving segment, means actuated by the cam follower for locking and unlocking the driving segment, spring means urgin the driving segment to rotate the driven gear segment and thus operate the release crank, stop means applicable to the lathe, and means on the cam engageable with the stop means to actuate the cam when the stop means is engaged thereby.

2. A device of the class described comprising a driven gear applicable to the lead screw release crank of a lathe carriage, a driving gear arranged to mesh therewith, a cam rotatable in the driving gear, a cam follower slidable in the driving gear, a locking pin arranged to enter the driving gear in back of the cam follower for locking and unlocking the driving gear, spring means urging the driving gear to rotate the driven gear segment and thus operate the release crank, stop means applicable to the lathe, and means on the cam engageable with the stop means to actuate the cam when the stop means is engaged thereby.

3. A device of the class described comprising a driven gear applicable to the lead screw release crank of a lathe carriage, a driving gear arranged to mesh therewith, a cam rotatable in the driving gear, a cam follower slidable in the driving gear, a locking pin arranged to enter the driving gear in back of the cam follower for locking and unlocking the driving gear, spring means urging the driving gear to rotate the driven gear segment and thus operate the release crank, stop means applicable to the lathe, means on the cam engageable with the stop means to actuate the cam when the stop means is engaged thereby, and means for urging the locking pin into a position for locking the driving gear against rotation.

4. A device of the class described comprising a driven gear applicable to the lead screw release crank of a lathe carriage, a driving gear arranged to mesh therewith, a cam rotatable in the driving gear, a cam follower slidable in the driving gear, a locking pin arranged to enter the driving gear in back of the cam follower for locking and unlocking the driving gear, spring means urging the driving gear to rotate the driven gear segment and thus operate the release crank, stop means applicable to the lathe, means on the cam engageable with the stop means to actuate the cam when the stop means is engaged thereby, means for urging the looking pin into a position for locking the driving gear against rotation, and means for rendering the last mentioned means inoperative.

5. A device of the class described comprising a driven gear segment applicable to the lead screw release crank of a lathe carriage, a driving gear adapted to mesh therewith, spring means associated with the driving gear adapted to be stressed thereby when the release crank is swung into lead screw-engaging position to cause the driving gear to urge the release crank to return to releasing position, means for releasably locking the driving gear against rotation under the influence of the spring means, stop means applicable to the lathe, and means adapted to be mounted on the lathe engageable with the stop means to effect a release of the locking means whereby the spring means can be effective to rotate the driving gear and thus shift the release crank to release position.

JOSEPH B. RUATTI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 193,850 Cooley Aug. 7, 1877 2,101,754 Randall Dec. 7, 1937 2,154,915 Ohera Apr. 18, 1939 FOREIGN PATENTS Number Country Date 27,652 Denmark May 9, 1921 

